Why couldn't this be used in a small car... ~1100kg... 50kw is enough to get it going, maybe not fast...
...
I'm looking for CHEAP alternatives for a small car conversion. 80kph, 50km range would be fine.

50kw is plenty for a commuter. My daily drive can be held down to 30kw if I'm careful - mainly used on 80km/h hills. RPM is your bigger issue as you have indicated. Keep in mind that they are force cooled in their native application.

Yep so a few problems.
1. It's an outrunner so a Big coffee tin spinning around in you engine bay.
2. Typical RPM is usually most ICE's peak so will need a good hi-revving gearbox (thin oil).
3. Airflow issues as suggested above FAN Power->RPM^2 vs High stall current on vehicle
4. Probably over rated power for selling so may never get 50kW.

I did put them up there as a comparison as my Handi only had 40kW so quite plausible use on a car.
But no one really twigged until now...

So 50kW will be FAST but not QUICK.
You should be able to do over 100kph.

To me it didn't really seem that good a value.
The Motenergy motors would probably be more durable for the price.

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